When the sum of the water and air temperatures is less than 120, the participants must be dressed for immersion with wetsuits, dry suits, or “warm when wet” clothing such as fleece or wool.

2. Hot Weather - The 103 Rule of Thumb:

When the heat index is more than 103, you are in danger of heat stress (see heat index chart below). Because high humidity magnifies the effect of high temperature on us, weathermen often call this a "feels like" temperature. The heat index values are developed for shady, light wind conditions. Exposure to full sunshine can increase the Heat Index dramatically. The National Weather Service recommends "extreme caution" when the Heat Index range of 91 to 103 and to be aware of heat stress "danger" in the range of 103-124.

If you would like to determine the heat index for a planned paddle you can find the information at:

Overheating can quickly progress to heat exhaustion and/or heat stroke which can cause serious injury or death. Contrary to popular belief simply maintaining adequate hydration and electrolytes will not preclude a heat illness accident. Experience has shown that if all four of the following conditions are present, a high potential for onset of heat illness exists.

a. High Air Temperature (88 degrees and above)

b. High Humidity (80% and above - it feels "muggy")

c. Low Wind (5 knots or less)

d. High Water Temperature (86 degrees and above)

If all four of the above conditions are present, or anticipated during a kayak trip, trip leaders should consider cancelling the trip or taking the following precautions:

·Plan trips earlier in the day.

·Stop frequently for water breaks and check that all have and use adequate hydration and electrolytes.

·Reduce trip distance and paddle speed.

·Avoid getting caught in open water, remote locations, or other situations where rescue would be difficult.

·Avoid long downwind legs on a hot day.

·Avoid the “doldrums” typically found adjacent to building storms and/ or in the transition period between the morning breeze and the afternoon sea breeze.

Symptoms of heat stress include; profuse sweating, headache, pale or red skin, nausea, muscle cramps, weakness, dizziness, lose of coordination, and many others. Once a participant starts to succumb to heat illness, it will be very difficult to cool the victim down and reverse the process. Towing a victim will hazard the rescuers to overheating.

If you, or anyone else in your group, have symptoms of heat stress, it's essential to